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Questions tagged [hobbyist]

The tag has no usage guidance.

0
votes
0answers
75 views

Phone on a breadbord

My current electronics project is to build a very simple custom phone from scratch. It is my own idea, with as ultimate goal to learn about microcontrollers and basic electronics. This is my set-up ...
2
votes
0answers
53 views

Hobby Project - Signal Frequency detector

Context: I have taken on a little side hobby project to learn by making a circuit which should be able to only go high when it sense an acoustic signal with a frequency around 40kHz. To do this I will ...
2
votes
2answers
204 views

Bandpass Filter: Single supply op amp design

I have taken on a hobby project and I am trying to make a circuit which would be able to identify an acoustic signal with a frequency of 40kHz. Here is the circuit of a band pass filter for this: ...
0
votes
1answer
78 views

Should I spread the pads out on the footprint of a THT LED?

I have a 4 pin RGB LED with a common anode. I'm trying to make my first PCB and I am creating the footprint for the LED now. I don't have a datasheet for the LEDs unfortunately. I have a ruler ...
0
votes
2answers
110 views

Do I need decoupling capacitors when I'm PWMing an LED?

I'm a hobbyist (well, less than a hobbyist really) trying to layout my first PCB design. I'm somewhat familiar with the concept of decoupling capacitors. I'm fading 3 LEDs in and out (really, it's ...
0
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1answer
47 views

using 7.62mm screw terminals on prototype board

What have people done to be able to use 7.62mm screw terminals on prototype boards? I am trying to prototype something use screw terminals that have 7.62mm posts, but the prototype boards do not have ...
3
votes
3answers
293 views

Simple, low precision, milliohmmeter

Would like to have a simple milliohmeter for car wiring checking. Precision is not important, it's not about 3 vs 4 mΩ, it's about 3 vs 30 vs 300 mΩ. Simple idea is a 1A floating current source (2 ...
0
votes
2answers
862 views

Replicate PCB design on stripboard

I'm thinking about making a DIY project (this one). I'm a complete n00b, I just have some theoretical knowledge about electronics from some university courses, and I'd like to learn some more. I was ...
1
vote
3answers
161 views

Could one actually build electronics without EE degree? [closed]

I understand that a teach yourself electronics book can "teach you electronics", but just how far can that take you developmentally? I want to have the ability to solve a problem requiring the ...
7
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7answers
2k views

Is it cheating if I use an SRAM chip as a register file? [closed]

I'm currently building my very own processor using discrete logic (74LSxx series and that) using my very own instruction set architecture. I am starting to rack up a bit of a bill because all the ...
1
vote
3answers
2k views

Power connectors: 2.1mm and 2.5mm, 1.35 and 1.7mm

I refer to DC power connectors used for a wide variety of common consumer devices. I notice that I have to specify between 2.1mm and 2.5mm when I want to purchase these online. Are the two ...
-2
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1answer
67 views

Cupboard lighting problem

I have some battery powered LED lights to go in a cupboard; and I have a 5-terminal magnetic alarm sensor to turn them on when the cupboard door opens. The problem is that the lights turn on when the ...
0
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2answers
2k views

Calculating current in a series circuit

Given the following circuit, it seems like we could use ohms law to conclude that current = voltage / resistance. With a source voltage of 3.3 and a resistance value of 220, current = 3.3 / 220 = .015 ...
1
vote
1answer
87 views

Understanding LED specifications (hobby kit)

I have an LED that looks like: It did not come with specs for the LED. In laymens terms, I'm trying to determine the technical term for the following descriptions. (What is the max amount of current ...
0
votes
3answers
434 views

Digital Rotary Encoder — Broken? Or am I misunderstanding how it works?

I apologize if this seems like a fundamental question, but I feel like I'm missing a fundamental understanding about digital rotary encoders, because none of my basic encoders are working as expected. ...
2
votes
5answers
2k views

What is a good alternative for the UA741 opamp in hobby projects?

Related to What's the uA741's appeal?, a lot of schematics use this rather dated opamp. My follow-up question would be: What is a good alternative? Of course if you have specific requirements ...
-2
votes
1answer
97 views

A good way to get into Electronics with just 2 hours per week? [closed]

I want to get into electronics but I only have 2 hours per week to spend time-wise and my budget is low. What are some good projects? Perhaps I should spend my time doing C programming challenges ...
1
vote
1answer
150 views

Tapping into a 4 AWG wire

I am part of a hobby project where we have a pair of fat, insulated #4 AWG stranded copper wires carrying +5V and ground. I want to tap into these wires every few inches to draw power off it (max draw ...
0
votes
2answers
294 views

Weak and Cheap Linear Actuator? [closed]

I have a tiny tube that sprays lubricant but I need it to move between some holes in a line. The total distance is only 10 inches. So imagine the holes like this: ...
0
votes
1answer
70 views

Control a knob on a Honeywell fan via ESP8266

Hey all I am wondering what all I would need in order to control this knob on my Honeywell 2-in 1 Air Circulator Fan, HT-9700 I am wanting to use a ESP8266 in order to control it via wifi. I know ...
1
vote
0answers
88 views

Low voltage LED bulb or jump into line voltage?

I'm not even sure if this is appropriate StackExchanage community for this but I wasn't sure where else this sort of question would fit. So I tinker with electronics here and there and primarily it ...
1
vote
1answer
47 views

Buying Low Volume Populated PCBs and Handling Passive PNs

New to Eagle PCB design. I plan on making a custom Beaglebone Black Wireless PCB, and so have pulled down the Eagle files. I'm a student and have a student license. This project will be too difficult ...
3
votes
1answer
1k views

Do I need to add smoothing capacitor for this setup

I'm trying to build an array (100) of WS2812B which are controlled over an Particle Photon, both are powered by a 10A/5V power supply. Powerwise: 10 WS2812B will be daisy-chained in one row Datawise:...
1
vote
2answers
191 views

How do you drill a homemade double sided pcb

I have a PCB that I am prototyping at home and it is double sided.... When I drill on one face the other face peels up a little. Does any one know how to avoid this problem?
6
votes
4answers
2k views

What is so special in the power MOSFETS IRFD120 and IRFD110?

I was trying out a hobby project and I was using the IRFD120 and IRFD110 power MOSFETs to control a motor. The transistors worked pretty fine and we simply ran out of them. When I went to buy some ...
3
votes
2answers
620 views

Is it safe to over-volt brushless out-runner dc motor on low load conditions?

I have a 1100KV brushless DC motor (turnigy d3548/4) rated maximum voltage 19V i want to run it at 25V assuming low load as i mostly need the higher rpm ! whats are the effects of this higher ...
0
votes
1answer
123 views

How to wire the mains to a transformer for end user safety?

Because this can be deadly, and is best left to someone qualified; advice for hobbyist projects on the web are reluctant to offer advice on safely handling mains connections. The get-around is to ...
1
vote
2answers
73 views

What is the term for a photo sensor that takes low-resolution, black-and white, closeup images?

For work I used to have to read and log 7-segment LCD numbers off this tiny (3cm x 1cm) screen tens of times per day. Now I have a webcam setup that reads it for me and does some OCR to automatically ...
0
votes
1answer
61 views

Solar powered 5W DC12V pump

I'm trying to power a little pump (http://www.amazon.com/gp/product/B00JWJIC0K) with a solar panel I have. I've stepped the voltage out of the panel down to 12V with a buck converter. The panel is ...
0
votes
1answer
186 views

Is this a limit switch design? What switches needed for this project?

I wish comments on how to best achieve a design involving two limit switches on a DC motor, but which does not reverse the motor. I've researched this design already on this forum; here's my work, I ...
17
votes
4answers
3k views

What well-known ICs have essentially no packaging?

As a kid I once found a calculator whose IC was protected only by a loose plastic cover. With the cover removed, and with appropriate lighting, I could make out distinct features of the IC– including ...
0
votes
1answer
316 views

Current Source version of TLC5940 (current sink LED PWM driver)?

Is there a current-source equivalent of a TLC5940 (current-sink) PWM LED driver? I'm working with a large number of linear resonant actuators (LRAs), each of which only uses ~50mA, but must be driven ...
5
votes
6answers
2k views

Would it be possible to make a solid state transistor by hand?

I am curious, would it be possible to fabricate a modern BJT/FET transistor with hobby/garage tools only if size and aesthetics was not important? Which materials would one use and how would one ...
0
votes
2answers
263 views

Checking my understanding of how hobby servo motors operate?

Can someone tell me if my understanding is correct please. The control signal to a hobby servo motor that is connected to an arduino operates by : In every 1 s there are fifty windows each of length ...
-4
votes
1answer
81 views

how can i using CPU8085 and PIO8155 crate an alarm circuit and program [closed]

example ; we have smoke sensor, speaker and my circuit.When Sensor has been active, speaker to sing it. i'm newbie in this topic. how can i do it like this circuit ?
2
votes
4answers
2k views

Mounting a PCB with velcro

I need a lo-fi way of mounting a PCB (Tessel plus RFID card) under a table. The easiest method by far would be velcro but I'm worried about static discharge frying my circuitry. Should I be?
2
votes
3answers
2k views

Is electronics an expensive hobby? [closed]

I recently just finished my Eagle schematic for a simple robot that moves and plan to order the parts and the PCB soon. Unfortunately with the soldering iron, helping hands, lights, solder, parts, and ...
2
votes
2answers
530 views

3 LEDs / 1 POT - fade each LED in turn as POT is changed in value ?

I'm looking for a simple (hopefully !) circuit which would allow a variable resistor to control the brightness of three different coloured LED's. As the variable resesistance is changed in value first ...
4
votes
4answers
710 views

Is there any way to use industrial sized IC's package in home project?

All actuals DSP or MCUs comes in BGA-like packages with numerous pins and very small size that make them hard to integrate in home project. Does anyone has knowledge of revolutionary breadboards, ...
0
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2answers
93 views

Help with wiring of stereo jack

Could someone point me in the right direction. What I'm doing here is I took the insides from a cheap Bluetooth speaker and I would like to rewire it to an headphone jack (male). I have the cable ...
2
votes
3answers
3k views

Powering 28 LEDs in series by 220VAC - simple stabilizer

I have a home-made thingy that I would like to use as a lightning in my living room. It contains 7*4=28 LEDs (red, 1.86V, ...
1
vote
5answers
459 views

How to cheaply switch between two sets of 7-input-wires?

I am trying to make a water level sensor. I want to use a single circuit for two water tanks. For this I need to be able to switch between two sets of 7-wire-inputs to the circuit (the 7 wires that ...
1
vote
2answers
2k views

How can I create a theatrical spark ejector?

I'm involved with an amateur theatre company (I do lighting, audio etc...) and would like to simulate a switch short-circuiting. I have also done a bit of magic in my time and have used "spark ...
29
votes
4answers
24k views

Building a hobbyist oscilloscope

I have a project that I've been thinking about for a little while, and I've come to the realization that at some point during its development, I'm going to need an oscilloscope. Okay, not a problem. ...
2
votes
2answers
1k views

Using an Arduino to Emulate a CD4021 Shift Register for Controlling an NES [duplicate]

This is probably a silly thing to do when I could wait for my CD4021s (74HC165Ns) to arrive and save myself the hassle but I feel as though this can be done and I'm simply missing something. I've ...
0
votes
1answer
236 views

Should I use Mathematica to understand circuit behavior? [closed]

I've just started learning about circuits from the "Foundations of Analog and Digital Electronic Circuits" book. KCL, KVL, element laws and linear circuits were easy to grasp but then I got the half-...
1
vote
2answers
6k views

Trigger a relay with a very low DC voltage

I want to light up a couple of LEDs using a relay to trigger this event. I have a very low DC voltage, about 0.15mV to 0.20mV and I want to somehow take this voltage to a relay, that will be also ...
7
votes
4answers
900 views

Ideal location to practice soldering

Sounds like a stupid question, but really hasn't been asked before, or I haven't found a post about it. Either way, here it is: I bought a soldering iron recently and am looking for a place in my ...
7
votes
2answers
1k views

What are the characteristics of a memristor?

This is an in-spirit follow-up to my earlier question. So I'm an electronics hobbyist, and I've been curious for a while about the proposed new component, the memristor. My research has turned up ...
8
votes
5answers
3k views

Does it make sense to measure components in-circuit in order to prove non-functioning?

When an electrical circuit is not working properly does it make sense to use a multimeter to measure/test the individual components in-circuit (without soldering them out), e.g. measure transistor ...